Target supply device and euv light generation apparatus

ABSTRACT

A target supply device may include a tank for storing a target material, a nozzle which is connected to the tank and outputs the target material, and a gas supply section for supplying the tank with gas. The gas supply section may include a booster which is connected to a gas line, boosts the gas supplied from the gas line, and outputs the boosted gas to the tank, a pressure sensor for measuring the pressure inside the tank, and a pressure controller which adjusts the pressure of the gas to be supplied to the tank on the basis of a measurement result from the pressure sensor.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of U.S. application Ser. No.15/260,625 filed Sep. 9, 2016, which is a continuation of InternationalApplication No. PCT/JP2015/062304, filed Apr. 22, 2015, which claims thebenefit of International Application No. PCT/JP2014/061839, filed Apr.28, 2014, the entire contents of both of which are incorporated hereinby reference.

BACKGROUND 1. Technical Field

The present disclosure relates to a target supply device and an extremeultraviolet (EUV) light generation apparatus.

2. Related Art

In recent years, semiconductor production processes have become capableof producing semiconductor devices with increasingly fine feature sizes,as photolithography has been making rapid progress toward finerfabrication. In the next generation of semiconductor productionprocesses, microfabrication with feature sizes at 45 nm to 70 nm, andfurther, microfabrication with feature sizes of 32 nm or less will berequired. In order to meet the demand for microfabrication with featuresizes of 32 nm or less, for example, an exposure apparatus is needed inwhich an apparatus for generating extreme ultraviolet (EUV) light at awavelength of approximately 13 nm is combined with a reduced projectionreflective optical system.

Three kinds of apparatuses for generating EUV light are known ingeneral, which include a Laser Produced Plasma (LPP) type apparatus inwhich plasma generated by irradiating a target material with a laserbeam is used, a Discharge Produced Plasma (DPP) type apparatus in whichplasma generated by electric discharge is used, and a SynchrotronRadiation (SR) type apparatus using synchrotron radiation.

SUMMARY

A target supply device according to an aspect of the present disclosure,which is configured to supply a target material, may include a tank, anozzle, and a gas supply section. The tank may be configured to storethe target material. The nozzle may be connected to the tank andconfigured to output the target material. The gas supply section may beconfigured to supply the tank with gas. The gas supply section mayinclude a booster, a pressure sensor, and a pressure controller. Thebooster may be connected to the gas line and configured to boost gassupplied from the gas line and supply the tank with the boosted gas. Thepressure sensor may be configured to measure pressure inside the tank.The pressure controller may be configured to adjust pressure of the gasto be supplied to the tank based on a measurement result from thepressure sensor.

An EUV light generation apparatus according to an aspect of the presentdisclosure, which includes a target supply device configured to supply atarget material, may irradiate the target material with a laser beam togenerate EUV light. The target supply device may include a tank, anozzle, and a gas supply section. The tank may be configured to storethe target material. The nozzle may be connected to the tank andconfigured to output the target material. The gas supply section may beconfigured to supply the tank with gas. The gas supply section mayinclude a booster, a pressure sensor, and a pressure controller. Thebooster may be connected to the gas line and configured to boost gassupplied from the gas line and supply the tank with the boosted gas. Thepressure sensor may be configured to measure pressure inside the tank.The pressure controller may be configured to adjust pressure of the gasto be supplied to the tank based on a measurement result from thepressure sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, selected embodiments of the present disclosure will bedescribed with reference to the accompanying drawings.

FIG. 1 schematically illustrates a configuration of an LPP type EUVlight generation apparatus.

FIG. 2 schematically illustrates a configuration of an EUV lightgeneration apparatus including a target supply device according to afirst embodiment.

FIG. 3 schematically illustrates a configuration of a booster.

FIG. 4 schematically illustrates a configuration of a target supplydevice that supplies a tank with gas using a gas bottle.

FIG. 5 schematically illustrates a configuration of a target supplydevice according to a second embodiment.

FIG. 6 schematically illustrates a configuration of a target supplydevice according to a third embodiment.

FIG. 7 schematically illustrates a configuration of a target supplydevice according to a fourth embodiment.

FIG. 8 schematically illustrates a configuration of an EUV lightgeneration system according to a fifth embodiment.

FIG. 9 schematically illustrates a configuration of an EUV lightgeneration system according to a sixth embodiment.

FIG. 10 schematically illustrates a configuration of a target supplydevice according to a seventh embodiment.

FIG. 11 is a flowchart illustrating operations performed by the targetsupply device according to the seventh embodiment.

FIG. 12 schematically illustrates a configuration of an EUV lightgeneration system according to an eighth embodiment.

FIG. 13 is a flowchart illustrating operations performed by the targetsupply device according to the eighth embodiment.

DETAILED DESCRIPTION

Hereinafter, selected embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Theembodiments to be described below are merely illustrative in nature anddo not limit the scope of the present disclosure. Further, theconfiguration(s) and operation(s) described in each embodiment are notall essential in implementing the present disclosure. Note that likeelements are referenced by like reference numerals and characters, andduplicate descriptions thereof will be omitted herein.

CONTENTS

-   1. Overview-   2. Overall Description of EUV Light Generation Apparatus-   2.1 Configuration-   2.2 Operation-   3. EUV Light Generation Apparatus Including Target Supply Device-   3.1 Terms-   3.2 First Embodiment-   3.2.1 Overview-   3.2.2 Configuration-   3.2.3 Operation-   3.3 Second Embodiment-   3.3.1 Configuration-   3.3.2 Operation-   3.4 Third Embodiment-   3.4.1 Configuration-   3.4.2 Operation-   3.5 Fourth Embodiment-   3.5.1 Configuration-   3.5.2 Operation-   3.6 Fifth Embodiment-   3.6.1 Configuration-   3.6.2 Operation-   3.7 Sixth Embodiment-   3.7.1 Configuration-   3.7.2 Operation-   3.8 Seventh Embodiment-   3.8.1 Configuration-   3.8.2 Operation-   3.9 Eighth Embodiment-   3.9.1 Configuration-   3.9.2 Operation-   3.10 Variation

1. Overview

According to an embodiment of the present disclosure, a target supplydevice, which is configured to supply a target material, may include atank, a nozzle, and a gas supply section. The tank may be configured tostore the target material. The nozzle may be connected to the tank andconfigured to output the target material. The gas supply section may beconfigured to supply the tank with gas. The gas supply section mayinclude a booster, a pressure sensor, and a pressure controller. Thebooster may be connected to a gas line and configured to boost gassupplied from the gas line and supply the tank with the boosted gas. Thepressure sensor may be configured to measure pressure inside the tank.The pressure controller may be configured to adjust pressure of the gasto be supplied to the tank based on a measurement result from thepressure sensor.

According to an embodiment of the present disclosure, an EUV lightgeneration apparatus, which includes a target supply device configuredto supply a target material, may irradiate the target material with alaser beam to generate EUV light. The target supply device may include atank, a nozzle, and a gas supply section. The tank may be configured tostore the target material. The nozzle may be connected to the tank andconfigured to output the target material. The gas supply section may beconfigured to supply the tank with gas. The gas supply section mayinclude a booster, a pressure sensor, and a pressure controller. Thebooster may be connected to a gas line and configured to boost gassupplied from the gas line and supply the tank with the boosted gas. Thepressure sensor may be configured to measure pressure inside the tank.The pressure controller may be configured to adjust pressure of the gasto be supplied to the tank based on a measurement result from thepressure sensor.

2. Overview of EUV Light Generation Apparatus 2.1 Configuration

FIG. 1 schematically illustrates an exemplary configuration of an LPPtype EUV light generation system. An EUV light generation apparatus 1may be used with at least one laser apparatus 3. Hereinafter, in thepresent application, a system that includes the EUV light generationapparatus 1 and the laser apparatus 3 is referred to as an EUV lightgeneration system 11. As shown in FIG. 1 and described in detail below,the EUV light generation apparatus 1 may include a chamber 2 and atarget supply device 7. The chamber 2 may be sealed airtight. The targetsupply device 7 may be mounted onto the chamber 2, for example, topenetrate a wall of the chamber 2. A target material to be supplied bythe target supply device 7 may include, but is not limited to, tin,terbium, gadolinium, lithium, xenon, or any combination thereof.

The chamber 2 may have at least one through-hole or opening formed inits wall. The chamber 2 may have a window 21 formed in its wall, throughwhich a pulse laser beam 32 outputted from the laser apparatus 3 maytravel into the chamber 2. An EUV collector mirror 23, for example,having a spheroidal reflecting surface may be provided inside thechamber 2. The EUV collector mirror 23 may have a multi-layeredreflective film formed on the spheroidal surface thereof. The reflectivefilm may include, for example, a molybdenum layer and a silicon layer,which are alternately laminated. The EUV collector mirror 23 can have afirst focus and a second focus, and is preferably positioned such thatthe first focus lies in a plasma generation region 25 and the secondfocus lies in an intermediate focus (IF) region 292. The EUV collectormirror 23 may have a through-hole 24 formed at the center thereof sothat a pulse laser beam 33 may travel through the through-hole 24.

The EUV light generation apparatus 1 may further include an EUV lightgeneration controller 5, a target sensor 4, and the like. The targetsensor 4 may have an imaging function and may be configured to detectthe presence, trajectory, position, speed, and the like of a droplet 27as a target.

Further, the EUV light generation apparatus 1 may include a connectionsection 29 for allowing the interior of the chamber 2 to be incommunication with the interior of the exposure apparatus 6. A wall 291having an aperture 293 may be provided in the connection section 29. Thewall 291 may be positioned such that the second focus of the EUVcollector mirror 23 lies in the aperture 293 formed in the wall 291.

The EUV light generation apparatus 1 may also include a laser beamdirection control unit 34, a laser beam focusing mirror 22, a targetcollector 28 for collecting droplets 27, and the like. The laser beamdirection control unit 34 may include an optical element for definingthe direction into which the pulse laser beam travels and an actuatorfor adjusting the position and the orientation or posture of the opticalelement.

2.2 Operation

With continued reference to FIG. 1, a pulse laser beam 31 outputted fromthe laser apparatus 3 may pass through the laser beam direction controlunit 34 and be outputted therefrom as the pulse laser beam 32 so as totravel through the window 21 and enter the chamber 2. The pulse laserbeam 32 may travel inside the chamber 2 along at least one laser beampath, be reflected by the laser beam focusing mirror 22, and beirradiated as a pulse laser beam 33 toward at least one droplet 27.

The target supply device 7 may be configured to output the droplet(s) 27toward the plasma generation region 25 in the chamber 2. The droplet 27may be irradiated with at least one pulse of the pulse laser beam 33.Upon being irradiated with the pulse laser beam 33, the droplet 27 canbe turned into plasma, and rays of reflected light 251 can be emittedfrom the plasma. The EUV light 252 included in the rays of reflectedlight 251 may be reflected selectively by the EUV collector mirror 23.The EUV light 252, which is reflected by the EUV collector mirror 23,may travel through the intermediate focus region 292 and be outputted tothe exposure apparatus 6. Here, the droplet 27 may be irradiated withmultiple pulses included in the pulse laser beam 33.

The EUV light generation controller 5 may be configured to integrallycontrol the EUV light generation system 11. The EUV light generationcontroller 5 may be configured to process image data of the droplet 27captured by the target sensor 4. Further, the EUV light generationcontroller 5 may be configured to control the timing when the droplet 27is outputted, the direction into which the droplet 27 is outputted, orthe like, for example. Furthermore, the EUV light generation controller5 may be configured to control the timing when the laser apparatus 3oscillates, the direction in which the pulse laser beam 32 travels, theposition at which the pulse laser beam 33 is focused, or the like, forexample. The various controls mentioned above are merely examples, andother controls may be added as necessary.

3. EUV Light Generation Apparatus Including Target Supply Device

3.1. Terms

Hereinafter, aside from descriptions that refer to FIG. 1, there arecases where terms regarding directions will be described based on XYZaxes illustrated in the drawings. Further, there are cases where termsregarding directions will be described based on FIG. 3 in descriptionsabout the configuration and operation of the booster. Note that theseexpressions do not express relationships with a gravitational direction10B.

Gas that is boosted by the booster is referred to as “boosted gas” insome cases.

In the descriptions about the configuration and operation hereinbelow,an “upstream side” means a side on which a gas line or a gas bottle islocated in a gas flow direction, and a “downstream side” means a side onwhich a tank is located in the gas flow direction.

3.2 First Embodiment 3.2.1 Overview

In a target supply device or an EUV light generation apparatus accordingto a first embodiment of the present disclosure, the gas supply sectionmay further include a pressure lowering section configured to lowerpressure of gas, which has been boosted by the booster, down to apredetermined pressure.

In the target supply device or the EUV light generation apparatusaccording to the first embodiment of the present disclosure, the gassupply section may further include a pressure accumulator disposedbetween the booster and the pressure lowering section.

In the target supply device or the EUV light generation apparatusaccording to the first embodiment of the present disclosure, the gassupply section may further include a gas purifying section configured toremove impurities from the gas which has been boosted by the booster.

In the target supply device or the EUV light generation apparatusaccording to the first embodiment of the present disclosure, the gaspurifying section may be disposed in a downstream side from the pressurelowering section.

In the target supply device or the EUV light generation apparatusaccording to the first embodiment of the present disclosure, the gassupply section may further include a particle filter configured toremove particles from the gas which has been boosted by the booster.

In the target supply device or the EUV light generation apparatusaccording to the first embodiment of the present disclosure, the gassupply section may further include a pressure stabilizer configured tostabilize the pressure of the gas which has been boosted by the booster.In the target supply device or the EUV light generation apparatusaccording to the first embodiment of the present disclosure, a pluralityof the pressure stabilizers may be provided, and one of a plurality ofthe pressure stabilizers may be the pressure lowering section.

3.2.2 Configuration

FIG. 2 schematically illustrates a configuration of an EUV lightgeneration apparatus that includes a target supply device according to afirst embodiment. FIG. 3 schematically illustrates a configuration of abooster.

An EUV light generation apparatus 1A may, as shown in FIG. 2, include achamber 2 and a target supply device 7A. The target supply device 7A mayinclude a target generation section 70A and a target control apparatus80A. A laser apparatus 3, a target sensor 4, and an EUV light generationcontrol system 5A may be electrically connected to a target controlapparatus 80A.

As shown in FIG. 2, the target generation section 70A may include atarget generator 71A, a gas supply section 73A, a temperature controlsection 78A, and a piezoelectric section 79A.

The target generator 71A may be formed of molybdenum, for example, whichis a material having a low reactivity with the target material 270. Thetarget generator 71A may include a tank 711A for storing the targetmaterial 270. The tank 711A may include a main body section 712A, abottom section 713A, and a lid section 714A.

The main body section 712A may have a cylindrical shape.

The bottom section 713A may be configured to block one end of the mainbody section 712A on a +Z direction side in an axial direction of themain body section 712A. The bottom section 713A may be integrated withthe main body section 712A.

The lid section 714A may be configured to block the other end of themain body section 712A on a −Z direction side in the axial direction ofthe main body section 712A. The lid section 714A may be configured to beseparated from the main body section 712A. The lid section 714A may befixed to the main body section 712A with use of a bolt (not shown in thedrawings). In this case, a space between the main body section 712A andthe lid section 714A may be sealed by fitting an O-ring (not shown inthe drawings) into a groove formed on a surface of the lid section 714Aon the +Z direction side.

A nozzle 718A for outputting the target material 270 within the tank711A as the droplets 27 to the inside of the chamber 2 may be providedin the tank 711A. The target generator 71A may be provided so that thetank 711A is positioned outside the chamber 2 and the nozzle 718A ispositioned inside the chamber 2.

A nozzle hole 719A may be provided to the nozzle 718A. The nozzle hole719A may have an opening at approximately the center of an end of thenozzle 718A on the +Z direction side. The diameter of the nozzle hole719A may be in the range of 3 to 15 pm. The nozzle 718A may be formed ofa material having a low wettability with the target material 270.Specifically, the material having a low wettability to the targetmaterial 270 may be a material whose angle of contact with the targetmaterial 270 is greater than 90°. The material having an angle ofcontact greater than or equal to 90° may be one of SiC, SiO₂, Al₂O₃,molybdenum, tungsten, and tantalum.

Depending on how the chamber 2 is arranged, it is not necessarily thecase that a pre-set output direction for the droplets 27 matches thegravitational direction 10B. The pre-set output direction for thedroplets 27 may be set to match a central axis of the nozzle hole 719A,and hereinafter referred to as a set output direction 10A. Theconfiguration may be such that the droplet 27 is outputted horizontallyor at an angle relative to the gravitational direction 10B.Incidentally, in the first embodiment, the chamber 2 may be arranged sothat the set output direction 10A and the gravitational direction 10Bmatch.

The lid section 714A may be provided with a pipe 721A. The pipe 721A maybe configured to penetrate through the lid section 714A so that a firstend of the pipe 721A is positioned inside the tank 711A.

The gas supply section 73A may supply the tank 711A with gas through thepipe 721A. The purity of the gas supplied to the tank 711A by the gassupply section 73 may be greater than or equal to 99.999%.

The gas supply section 73A may include a booster 731A, a gas purifyingsection 732A, a particle filter 733A, a buffer tank 734A as a pressurestabilizer, a pressure sensor 735A, and a pressure controller 736A.

The booster 731A may be an air-driven gas booster manufactured by HaskelInternational, Inc. (model no.: AGT-7/30, suction gas pressure: 1.0 MPa,discharge gas pressure: 20.7 MPa, flow rate: 0.07 L/min (Normal)), forexample.

The booster 731A may be connected to a second end of the pipe 721A. Thebooster 731A may be connected to a gas line 730A through a pipe 722A.The gas line 730A may be a low-pressure gas line which can be installedin a factory at a moderate price. The gas line 730A may be configured tosupply gas at the pressure of approximately 1 MPa. The gas supplied fromthe gas line 730A may be inert gas such as argon, helium, and nitrogen,or may be hydrogen.

The booster 731A may boost the gas supplied from the gas line 730A, andoutput the boosted gas to the pipe 721A. As shown in FIG. 3, the booster731A may include an air barrel 741A. The air barrel 741A may have a boxshape. The air barrel 741A may include a cylindrical portion 742A, afirst closed portion 743A, and a second closed portion 744A.

The cylindrical portion 742A may have a cylindrical shape.

The first closed portion 743A may close an upper end of the cylindricalportion 742A. A first end of a pipe 745A and a first end of a pipe 746Amay be connected to a different position of the first closed portion743A, respectively. The pipes 745A and 746A may be connected to the airbarrel 741A such that the interior of each of the pipes 745A and 746A isin communication with the interior of the air barrel 741A. A drive airsupplier 747A may be connected to a second end of the pipe 745A. A spool748A may be connected to a second end of the pipe 746A. An exhaust pipe749A may be connected to the spool 748A.

A first pilot valve 750A may be disposed at a position of the firstclosed portion 743A to which neither the pipe 745A nor the pipe 746A isconnected. The first pilot valve 750A may be disposed such that part ofthe first pilot valve 750A is positioned inside the air barrel 741A.

The second closed portion 744A may close a lower end of the cylindricalportion 742A. A through-hole 751A may be formed at approximately thecenter of the second closed portion 744A.

A first end of a pipe 752A and a first end of a pipe 753A may beconnected to a different position of the second closed portion 744A,respectively. The pipes 752A and 753A may be connected to the air barrel741A such that the interior of each of the pipes 752A and 753A is incommunication with the interior of the air barrel 741A. The drive airsupplier 747A may be connected to a second end of the pipe 752A. Thespool 748A may be connected to a second end of the pipe 753A.

The second pilot valve 754A may be disposed at a position of the secondclosed portion 744A to which neither the pipe 752A nor the pipe 753A isconnected. The second pilot valve 754A may be disposed such that part ofthe second pilot valve 754A is positioned inside the air barrel 741A.

Drive air may be supplied to the interior of the air barrel 741A throughthe pipe 745A or the pipe 752A by the drive air supplier 747A.

Through the pipe 746A or the pipe 753A, the spool 748A may exhaust airinside the air barrel 741A through the exhaust pipe 749A.

A gas barrel 755A may be disposed at the second closed portion 744A ofthe air barrel 741A so as to extend downward. The gas barrel 755A may beintegrated with the air barrel 741A.

The gas barrel 755A may have a cylindrical shape of which lower end isclosed. An inner diameter of the gas barrel 755A may be smaller than aninner diameter of the cylindrical portion 742A. The gas barrel 755A maybe disposed such that the pipes 752A and 753A, and the second pilotvalve 754A are positioned outside the gas barrel 755A. The gas barrel755A may be disposed such that the center of the through-hole 751A islocated at the center of the gas barrel 755A in a radial directionthereof.

A first check valve 756A and a second check valve 764A may be disposedat a different position on a side surface of the gas barrel 755A on thelower-end side, respectively.

The first check valve 756A may have a cylindrical main body section757A. The main body section 757A may be formed so as to extend to theoutside of the gas barrel 755A. A distal end of the main body section757A may be connected to the gas line 730A through the pipe 722A. Theinterior of the main body section 757A may be in communication with theinterior of the gas barrel 755A through a through-hole 758A formed onthe side surface of the gas barrel 755A. An inner diameter of thethrough-hole 758A may be smaller than an inner diameter of the main bodysection 757A. Thereby, a ring-shaped spring contact portion 759A can beformed outside the through-hole 758A.

An inclined surface section 760A may be formed at the distal end of themain body section 757A so as to be located inside the main body section757A. The inclined surface section 760A may have a shape such that adiameter of the inclined surface section 760A is decreased as thedistance from the gas barrel 755A is increased. Thereby, a through-hole761A having an inner diameter smaller than an inner diameter of the mainbody section 757A can be formed at the distal end of the main bodysection 757A.

A ball 762A may be disposed inside the main body section 757A. Adiameter of the ball 762A may be smaller than the inner diameter of themain body section 757A and larger than the inner diameter of thethrough-hole 761A.

A spring 763A may be disposed inside the main body section 757A. Thespring 763A may be a coil spring. The spring 763A may be disposed suchthat one end of a spiral of the spring 763A in an axial directionthereof comes into contact with the spring contact portion 759A and theother end thereof comes into contact with the ball 762A.

The second check valve 764A may have the same structure as that of thefirst check valve 756A. The second check valve 764A may include a mainbody section 765A, a through-hole 766A, an inclined surface section767A, a spring contact portion 768A, a through-hole 769A, and a ball770A.

The main body section 765A may have a cylindrical shape. The distal endof the main body section 765A may be connected to the gas purifyingsection 732A through the pipe 721A. The interior of the main bodysection 765A may be in communication with the interior of the gas barrel755A through a through-hole 766A formed on the side surface of the gasbarrel 755A. An inclined surface section 767A may be disposed inside themain body section 765A at a side on which the gas barrel 755A islocated. The inclined surface section 767A may have a shape such that adiameter of the inclined surface section 767A is decreased as thedistance from the gas barrel 755A is decreased. Thereby, the innerdiameter of the through-hole 766A can be smaller than the inner diameterof the main body section 765A.

A ring-shaped spring contact portion 768A may be formed at the distalend of the main body section 765A. An opening of the spring contactportion 768A may be a through-hole 769A having an inner diameter smallerthan the inner diameter of the main body section 765A.

A ball 770A, which has a diameter smaller than the inner diameter of themain body section 765A and larger than the inner diameter of thethrough-hole 766A, may be disposed inside the main body section 765A.

A spring 771A, which is a coil spring, may be disposed inside the mainbody section 765A. The spring 771A may be disposed such that one end ofa spiral of the spring 771A in an axial direction thereof comes intocontact with the spring contact portion 768A and the other end thereofcomes into contact with the ball 770A.

The booster 731A may include an air piston 772A, a gas piston 773A, anda rod 774A.

The air piston 772A may be formed as a circular plate having an outerdiameter that is approximately the same as an inner diameter of thecylindrical portion 742A. The air piston 772A may be disposed inside thecylindrical portion 742A such that a thickness direction of the airpiston 772A is parallel to an axial direction of the cylindrical portion742A. An O-ring (not shown in the drawings) may be fit into a grooveformed on an outer circumferential surface of the air piston 772A so asto prevent the drive air supplied to a first space 775A located abovethe air piston 772A from flowing into a second space 776A located belowthe air piston 772A.

The gas piston 773A may be formed as a circular plate having an outerdiameter that is approximately the same as an inner diameter of the gasbarrel 755A. The gas piston 773A may be disposed inside the gas barrel755A such that a thickness direction of the gas piston 773A is parallelto an axial direction of the gas barrel 755A. An O-ring (not shown inthe drawings) may be fit into a groove formed on an outercircumferential surface of the gas piston 773A so as to prevent gas in athird space 777A located below the gas piston 773A from flowing into afourth space 778A located above the gas piston 773A.

The rod 774A may be formed as a round bar having an outer diameter thatis approximately the same as an inner diameter of the through-hole 751A.The rod 774A may be inserted through the through-hole 751A. The airpiston 772A may be connected to an upper end of the rod 774A. The gaspiston 773A may be connected to a lower end of the rod 774A. An O-ring(not shown in the drawings) may be fit into a groove formed on an innercircumferential surface of the through-hole 751A so as to prevent thedrive air in the second space 776A from flowing into the fourth space778A.

For example, as shown by chain double-dashed lines in FIG. 3, it may beconfigured that the spool 748A allows the first space 775A to be incommunication with the outside of the booster 731A through the pipe 746Aand the exhaust pipe 749A and that the second space 776A is sealedairtight, when the air piston 772A is brought in contact with the secondpilot valve 754A. The drive air supplier 747A may supply only the secondspace 776A with the drive air. Thereby, the air in the first space 775Ais exhausted at the same time as the air piston 772A and the gas piston773A moves upward, and the pressure in the third space 777A can belowered. When the pressure in the third space 777A is lowered, the ball770A is brought into close contact with the inclined surface section767A such that the second check valve 764A is closed, and concurrently,the ball 762A moves away from the inclined surface section 760A suchthat the first check valve 756A is opened, and thereby the gas in thegas line 730A can be filled into the third space 777A.

In the case where the amount of the gas filled into the third space 777Ais increased, as shown by solid lines in FIG. 3, the air piston 772A canbe brought in contact with the first pilot valve 750A. It may beconfigured that the spool 748A allows the second space 776A to be incommunication with the outside of the booster 731A through the pipe 753Aand the exhaust pipe 749A and that the first space 775A is sealedairtight, when the air piston 772A is brought in contact with the firstpilot valve 750A. The drive air supplier 747A may stop supplying thesecond space 776A with the drive air, and may supply only the firstspace 775A with the drive air. Thereby, the air in the second space 776Acan be exhausted, and concurrently the air piston 772A and the gaspiston 773A can move downward, and the pressure in the third space 777Acan be increased. When the pressure in the third space 777A isincreased, the ball 762A is brought into close contact with the inclinedsurface section 760A such that the first check valve 756A is closed, andconcurrently, the ball 770A moves away from the inclined surface section767A such that the second check valve 764A is opened, and thereby thegas boosted by the gas barrel 755A can be supplied to the gas purifyingsection 732A.

The gas purifying section 732A may be disposed in the pipe 721A suchthat the gas purifying section 732A is closer to the tank 711A than thebooster 731A is. The gas purifying section 732A may remove impurities inthe boosted gas supplied from the booster 731A. The impurities in theboosted gas may be an organic component such as a lubricant mixed intothe booster 731A, or oxygen. Thereby, it is possible to preventgeneration of a product of a reaction between the target material 270and the impurities within the tank 711A. As a result, it is possible toprevent the product of a reaction from blocking the nozzle 718A. The gaspurifying section 732A may be an adsorption-type gas purifying sectionor a getter-type gas purifying section.

The particle filter 733A may be disposed in the pipe 721A such that theparticle filter 733A is closer to the tank 711A than the gas purifyingsection 732A is. The particle filter 733A may remove particles in theboosted gas outputted from the booster 731A. The particles in theboosted gas may be generated from a sliding component of the booster731A. The sliding component which generates the particles may be theO-ring provided to the gas piston 773A, or the gas barrel 755A broughtinto contact with the O-ring. Thereby, it is possible to prevent theparticles from entering the tank 711A and blocking the nozzle 718A. Theparticle filter 733A may be a clean gas filter having a filtrationrating of approximately 0.02 μm. The filter element for the particlefilter 733A may be a PTFE membrane or the like.

A pipe 723A may be connected to the pipe 721A such that the pipe 723A iscloser to the tank 711A than the particle filter 733A is. A first end ofthe pipe 723A may be connected to a side surface of the pipe 721A. Thebuffer tank 734A may be disposed at a second end of the pipe 723A.

The bulk of the buffer tank 734A may be larger than a total volume ofall gas flow channels located between the booster 731A and the tank711A. The buffer tank 734A may decrease pressure fluctuation of theboosted gas which occurs inside the pipe 721A. The booster 731A booststhe gas by vertically moving the gas piston 773A, and therefore thepressure fluctuation of the boosted gas corresponding to a reciprocationcycle of the gas piston 773A may occur. The buffer tank 734A maydecrease pressure fluctuation of the boosted gas which has been boostedby the booster 731A. The extent of the pressure fluctuation, which hasbeen decreased by the buffer tank 734A, may be less than 10% of thepressure which has been adjusted by the pressure controller 736A.

A pipe 724A may be connected to the pipe 721A such that the pipe 724A iscloser to the tank 711A than the buffer tank 734A is. A first end of thepipe 724A may be connected to the side surface of the pipe 721A. Thepressure sensor 735A may be disposed at a second end of the pipe 724A.

The pressure sensor 735A may be electrically connected to a valvecontroller 737A, to be described later, of the pressure controller 736A.The pressure sensor 735A may measure the pressure inside the pipe 724Aand transmit a signal corresponding to the measured pressure to thevalve controller 737A. The pressure inside the pipe 724A can beapproximately the same as the pressure inside the pipe 721A and thepressure inside the tank 711A. Namely, the pressure sensor 735A canmeasure the pressure inside the tank 711A.

The pressure controller 736A may adjust the pressure of the boosted gassupplied to the tank 711A based on the measurement result from thepressure sensor 735A. The pressure controller 736A may include a firstvalve V1, a second valve V2, and the valve controller 737A.

The first valve V1 may be disposed at a segment between a connectingportion between the pipe 721A and the pipe 723A and a connecting portionbetween the pipe 721A and the pipe 724A.

A pipe 725A may be connected to a segment between the connecting portionbetween the pipe 721A and the pipe 724A and the connecting portionbetween the pipe 721A and the first valve V1. A first end of the pipe725A may be connected to the side surface of the pipe 721A. A second endof the pipe 725A may be opened. The second valve V2 may be disposed inthe middle of the pipe 725A.

The pipes 721A, 722A, 723A, 724A, and 725A may be made of stainlesssteel, for example.

The first valve V1 and the second valve V2 may be any one of a gatevalve, a ball valve, a butterfly valve, and the like. The first valve V1and the second valve V2 may be a valve of the same type or a differenttype.

The valve controller 737A may be electrically connected to the firstvalve V1 and the second valve V2. The target control apparatus 80A maytransmit a signal regarding the first valve V1 and the second valve V2to the valve controller 737A. The opening/closing of the first valve V1and the second valve V2 may be switched independently from each otherbased on the signal transmitted from the valve controller 737A.

When the first valve V1 is opened, the boosted gas supplied from the gasline 730A can be supplied through the pipe 721A to the inside of thetank 711A of the target generator 71A. In the case where the secondvalve V2 is closed, it is possible to prevent the boosted gas inside thepipe 721A and the tank 711A from being discharged from the second end ofthe pipe 725A to the outside of the pipe 725A. Consequently, when thesecond valve V2 is closed at the same time as the first valve V1 isopened, the pressure inside the tank 711A can be increased up to thepressure which is equivalent to the pressure boosted by the booster731A. Thereafter, the pressure inside the tank 711A can be maintained atthe pressure which is equivalent to the pressure boosted by the booster731A.

When the first valve V1 is closed, it is possible to prevent the boostedgas from being supplied through the pipe 721A to the inside of the tank711A. When the second valve V2 is opened, the boosted gas inside thepipe 721A and the tank 711 can be discharged from the second end of thepipe 724A to the outside of the pipe 725A due to the difference betweenthe pressure inside the pipe 721A and the tank 711A and the pressureoutside the pipe 721A and the tank 711A. Thereby, when the second valveV2 is opened at the same time as the first valve V1 is closed, thepressure inside the tank 711A can be lowered.

The temperature control section 78A may be configured to control thetemperature of the target material 270 within the tank 711A. Thetemperature control section 78A may include a heater 781A, a heaterpower source 782A, a temperature sensor 783A, and a temperaturecontroller 784A. The heater 781A may be provided on an outercircumferential surface of the tank 711A. The heater power source 782Amay cause the heater 781A to produce heat by supplying power to theheater 781A based on a signal from the temperature controller 784A. As aresult, the target material 270 within the tank 711A can be heated viathe tank 711A.

The temperature sensor 783A may be provided on the outer circumferentialsurface of the tank 711A, at the location close to the nozzle 718A, ormay be provided within the tank 711A. The temperature sensor 783A may beconfigured to detect a temperature primarily at a location where thetemperature sensor 783A is installed as well as the vicinity thereof inthe tank 711A, and to send a signal corresponding to the detectedtemperature to the temperature controller 784A. The temperature at thelocation where the temperature sensor 783A is installed and the vicinitythereof can be substantially the same as the temperature of the targetmaterial 270 within the tank 711A.

The temperature controller 784A may be configured to output, to theheater power source 782A, a signal for controlling the temperature ofthe target material 270 at a predetermined temperature, based on asignal from the temperature sensor 783A.

The piezoelectric section 79A may include a piezoelectric element 791Aand a power source 792A. The piezoelectric element 791A may be providedon an outer circumferential surface of the nozzle 718A within thechamber 2. Instead of the piezoelectric element 791A, a mechanismcapable of applying vibrations to the nozzle 718A at high rate may beprovided. The power source 792A may be electrically connected to thepiezoelectric element 791A via a feedthrough 793A. The power source 792Amay be electrically connected to the target control apparatus 80A.

The target generation section 70A may be configured to generate thedroplets 27 by generating a jet 27A by a continuous jet method andvibrating the jet 27A outputted from the nozzle 718A.

3.2.3 Operation

FIG. 4 schematically illustrates a configuration of a target supplydevice that supplies a tank with gas using a gas bottle.

Note that the following describes operations performed by the targetsupply device 7A using a case where the target material 270 is tin as anexample.

A target supply device shown in FIG. 4 may have the same configurationas that of the target supply device 7A of the first embodiment exceptthat an inert gas bottle 721 is adopted instead of the booster 731A, thegas purifying section 732A, the particle filter 733A, and the buffertank 734A.

In such a target supply device, the target control apparatus 80Atransmits a signal to the temperature control section 78A so as to heatthe target material 270 within the target generator 71A up to apredetermined temperature that is equal to or greater than a meltingpoint of the target material 270.

The target control apparatus 80A may transmit a signal of predeterminedfrequency to the piezoelectric element 791A. Thereby, the piezoelectricelement 791A may vibrate so as to periodically generate the droplet 27from the jet 27A.

The target control apparatus 80A may transmit a signal to the valvecontroller 737A such that the pressure inside the tank 711A of thetarget generator 71A is set to a target pressure Pt. The valvecontroller 737A may control the opening/closing of the first valve V1and the second valve V2 such that a value of the difference ΔP betweenpressure P measured by the pressure sensor 735A and the target pressurePt becomes smaller. Thereby, the inert gas within the inert gas bottle721 may be supplied to the inside of the tank 711A, such that thepressure inside the tank 711A is stable at the target pressure Pt. Whenthe pressure inside the tank 711A reaches the target pressure Pt, thejet 27A is outputted from the nozzle 718A, and the droplet 27 can begenerated in accordance with the vibration of the nozzle 718A.

In order to improve EUV light output stability, it may be required toincrease the interval between the droplets 27. In the case where theinterval between the droplets 27 is small, in some cases, influence ofplasma for generating the EUV light can disturb a trajectory of thedroplet 27 to be irradiated with the laser beam next. In the case wherethe trajectory of the droplet 27 is disturbed, the laser beam may not beirradiated to an appropriate position of the droplet 27, and as aresult, the EUV light output may be fluctuated.

In order to suppress such a phenomenon, the interval between thedroplets 27 can be increased, so as to decrease the influence of theplasma for the droplet 27 to be irradiated with the laser beam next. Forthis purpose, repetition frequency for generating the EUV light can belowered. However, in order to maintain the EUV light output, it may benecessary to increase the energy of the EUV light. In the case where theenergy of the EUV light is increased, it is necessary to improve thelaser output, and the cost can be higher.

Accordingly, in order to maintain the repetition frequency of the EUVlight output as well as to increase the interval between the droplets27, the necessity of speeding up the output of the droplet 27 can beincreased.

In the case where the droplet 27 is outputted at the speed ofapproximately 50 m/s, for example, the pressure to be supplied to thetank 711A can be required to be approximately 12 MPa. In contrast,initial fill pressure for the inert gas bottle 721 can be approximately27 MPa.

The output of the droplets 27 results in gas consumption, and thereforethe pressure inside the inert gas bottle 721 can be lowered from theinitial fill pressure. When the pressure inside the inert gas bottle 721falls below the level of the pressure to be supplied to the tank 711A,it becomes impossible for the inert gas bottle 721 to supply the tank711A with the pressure necessary for outputting the droplet 27, andtherefore it can be required to replace the inert gas bottle 721 withanother one.

In the case of speeding up the output of the droplet 27, it can berequired to increase the pressure to be supplied to the tank 711A. Sincethe initial fill pressure for the inert gas bottle 721 is limited by thespecification of the container of the gas bottle, it can be difficult toreadily increase the initial fill pressure for the inert gas bottle 721.Therefore, in the case of speeding up the output of the droplet 27, itcan be required to replace the inert gas bottle 721 with another onemore frequently.

On the contrary, it is also possible to adopt a method of supplyinghigh-pressure gas for use in the target generation section 70A from agas facility of a semiconductor factory. However, in order to install agas facility for supplying gas at several tens of MPa, special pipes,valves, and the like with high pressure resistance are necessary, andtherefore the cost can be higher and it can take a lot of man-hours forsafety management of the high-pressure gas facility.

In order to improve such a situation, the target supply device 7A may beconfigured as shown in FIG. 2.

In the target supply device 7A shown in FIG. 2, the booster 731A mayboost the gas supplied from the gas line 730A and supply the boosted gasto the pressure controller 736A, when the valve controller 737A of thepressure controller 736A controls the opening/closing of the first valveV1 and the second valve V2, so that the pressure inside the tank 711Areaches the target pressure Pt.

As a preparation for outputting the droplet 27, the third space 777A isfilled with the gas supplied from the gas line 730A, the gas piston 773Aof the booster 731A moves upward to a position shown by the solid linesin FIG. 3, and the air piston 772A is brought in contact with the firstpilot valve 750A. Then, the booster 731A may cause the air piston 772Aand the gas piston 773A to move downward. Thereby, at the same time asthe first check valve 756A is closed, the second check valve 764A isopened, and the gas inside the third space 777A can be boosted andsupplied to the pressure controller 736A. Concurrently, the booster 731Amay cause the air piston 772A and the gas piston 773A to move downwardsuch that the flow rate of the boosted gas to be supplied to thepressure controller 736A through the second check valve 764A becomesapproximately 2.33 L/min (Normal).

In the case where the gas of approximately 1 MPa is boosted up toapproximately 14 MPa and the bulk of a target of which pressure is to beboosted is set to 12 L, it can be assumed that it takes 12 hours tocomplete the pressure boosting. Regarding the bulk of the target ofwhich pressure is to be boosted, it may be assumed that the bulk of thebuffer tank 734A as a typical example is set to 10 L, and the bulk ofeach of the tank 711A and the pipes 721A, 723A, and 724A is set to 2 L.

Moreover, in some cases, the output of the droplet 27 can be stopped sothat the pressure inside the tank 711A becomes about 1 atmosphere (0.1MPa). In this case, on the assumption that the pressure inside thebuffer tank 734A having the bulk of 10 L is maintained at 12 MPa, thebulk of the target of which pressure is to be boosted upon the firstboosting can be 2 L. In this case, on the assumption that 12-hourboosting time is ensured until the next output of the droplet 27, theflow rate of the boosted gas to be supplied to the pressure controller736A may be 0.39 L/min (Normal).

Namely, during the preparation for outputting the droplet 27, thebooster 731A may supply the boosted gas of approximately 12 MPa to thepressure controller 736A at the flow rate in the range of 0.35 L/min(Normal) to 2.4 L/min (Normal).

The boosted gas supplied from the booster 731A can be supplied to thegas purifying section 732A. The boosted gas supplied to the gaspurifying section 732A, from which impurities are removed by the gaspurifying section 732A, can be supplied to the particle filter 733A. Theboosted gas supplied to the particle filter 733A, from which particlesare removed by the particle filter 733A, can be supplied to the buffertank 734A and the pressure controller 736A. The pressure fluctuation ofthe boosted gas supplied to the pressure controller 736A can bedecreased in the buffer tank 734A. The pressure controller 736A mayadjust the pressure of the boosted gas, of which pressure fluctuationhas been decreased, and supply the boosted gas thus adjusted to theinside of the tank 711A. When the pressure inside the tank 711A reachesthe target pressure Pt, the jet 27A is outputted from the nozzle 718A,and the droplet 27 can be generated.

In a waiting state in which the pressure inside the tank 711A ismaintained at 12 MPa for the purpose of outputting the droplet 27 at anytime, the consumed amount of the boosted gas in the pressure controller736A can be 9.44 cc/min (Normal). The consumed amount of the boosted gasin this case may be an amount of the boosted gas discharged from thepipe 725A upon the second valve V2 of the pressure controller 736A beingopened.

Moreover, while the droplet 27 is being outputted, the consumed amountof the boosted gas in the pressure controller 736A can be 12.44 cc/min(Normal). The consumed amount of the boosted gas in the pressurecontroller 736A may be the sum of the consumed amount of the boosted gasupon the second valve V2 being opened (9.44 cc/min (Normal)) and theconsumed amount of the boosted gas upon the droplet 27 being pushed outof the nozzle 718A (3 cc/min (Normal)). The consumed amount of theboosted gas may be supposed on the assumption that the droplet 27, whichis tin having a diameter of 20 μm, is outputted by applying the pressureof 12 MPa at the frequency of 100 kHz.

Namely, in the waiting state until the droplet 27 is outputted or whilethe droplet 27 is being outputted, the booster 731A may supply theboosted gas of approximately 12 MPa to the pressure controller 736A atthe flow rate in the range of 9.4 cc/min (Normal) to 12.5 cc/min(Normal).

In accordance with the consumption of the boosted gas as describedabove, the air piston 772A and the gas piston 773A of the booster 731Acan move downward. Thereby, even when the droplet 27 continues to beoutputted and the boosted gas is consumed, the pressure inside the tank711A can be maintained at the target pressure Pt.

When the air piston 772A moves downward to a position shown by the chaindouble-dashed lines in FIG. 3 and the air piston 772A is brought incontact with the second pilot valve 754A, the booster 731A may move theair piston 772A and the gas piston 773A upward. Thereby, the secondcheck valve 764A is closed so as to stop supplying the boosted gas, andthe first check valve 756A is opened so as to supply the gas from thegas line 730A to the inside of the third space 777A. Then, when the airpiston 772A moves upward to the position shown by the solid lines inFIG. 3 and comes in contact with the first pilot valve 750A, asdescribed above, the booster 731A may cause the air piston 772A and thegas piston 773A to move downward and restart supplying the pressurecontroller 736A with the boosted gas.

The period of time from when the booster 731A stops supplying theboosted gas to when the booster 731A restarts supplying the boosted gasmay be, even in the case where the droplet 27 continues to be outputtedand the boosted gas continues to be consumed during this period of time,a length in which the pressure inside the tank 711A is maintained at thetarget pressure Pt.

Accordingly, even in the case where the boosted gas is consumed inaccordance with the output of the droplets 27, the booster 731A booststhe gas from the gas line 730A and supplies the pressure controller 736Awith the boosted gas, and thereby it is possible to continue to supplythe tank 711A with the high-pressure boosted gas. As a result, withoutreplacing the inert gas bottle, it is possible to speed up the output ofthe droplet 27. Further, since the gas from the gas line 730A which canbe installed in a factory at a moderate price is boosted and supplied,it is possible to prevent the cost from being higher, and safetymanagement of the high-pressure gas facility can be unnecessary.

Since the buffer tank 734A decreases pressure fluctuation of the boostedgas, it becomes possible to control the pressure with a high degree ofaccuracy by the pressure controller 736A. As a result, the outputstability of the droplet 27, such as the speed for outputting thedroplet 27, the interval between the droplets 27, and the angle foroutputting the droplet 27, can be improved.

3.3 Second Embodiment 3.3.1 Configuration

FIG. 5 schematically illustrates a configuration of a target supplydevice according to a second embodiment.

A target supply device 7B of the second embodiment may have the sameconfiguration as that of the target supply device 7A of the firstembodiment except the provision of a gas supply section 73B.

The gas supply section 73B may have the same configuration as that ofthe gas supply section 73A of the first embodiment except that the gassupply section 73B further includes a booster 731B which is similar tothe booster 731A.

The booster 731B may be disposed at a segment between the booster 731Aand the gas purifying section 732A in the pipe 721A.

3.3.2 Operation

Operations performed by the target supply device 7B are described.

Hereinbelow, the description of the operations which are the same asthose of the first embodiment will be omitted.

When the pressure controller 736A controls the pressure such that thepressure inside the tank 711A reaches the target pressure Pt in thetarget supply device 7B, the booster 731A may boost the gas suppliedfrom the gas line 730A and supply the booster 731B with the boosted gas.The booster 731B may further boost the boosted gas from the booster731A. The boosted gas, which has been boosted by the booster 731B, canbe supplied to the pressure controller 736A through the gas purifyingsection 732A, the particle filter 733A, and the buffer tank 734A.

Thereby, the pressure controller 736A can be supplied with the boostedgas at the pressure higher than that of the first embodiment.

When the pressure inside the tank 711A reaches the target pressure Pt,the jet 27A is outputted from the nozzle 718A, such that the droplet 27can be generated.

3.4 Third Embodiment 3.4.1 Configuration

FIG. 6 schematically illustrates a configuration of a target supplydevice according to a third embodiment.

A target supply device 7C of the third embodiment may have the sameconfiguration as that of the target supply device 7A of the firstembodiment except the provision of a gas supply section 73C.

A gas supply section 73C may have the same configuration as that of thegas supply section 73A of the first embodiment except that a pressureregulator 738C as a pressure stabilizer is provided instead of thebuffer tank 734A.

The pressure regulator 738C may be disposed at a segment between theparticle filter 733A and the first valve V1 in the pipe 721A. The pipe723A may not be necessarily connected to the pipe 721A. The material ofdiaphragm of the pressure regulator 738C may be PTFE(polytetrafluoroethylene), EPM (ethylene-propylene rubber), EPDM(ethylene-propylene-diene rubber), fluoro rubber, or the like. Thepressure regulator 738C may decrease the pressure fluctuation whichoccurs inside the pipe 721A. The extent of pressure fluctuation, whichhas been decreased by the pressure regulator 738C, may be less than 10%of the pressure which has been adjusted by the pressure controller 736A.

The bulk of the configuration for decreasing the pressure fluctuationcan be reduced by using the pressure regulator 738C instead of thebuffer tank 734A as described above.

3.4.2 Operation

Operations performed by the target supply device 7C are described.

Hereinbelow, the description of the operations which are the same asthose of the first embodiment will be omitted.

When the pressure controller 736A controls the pressure such that thepressure inside the tank 711A reaches the target pressure Pt in thetarget supply device 7C, the booster 731A may boost the gas suppliedfrom the gas line 730A. The boosted gas, which has been boosted by thebooster 731A, can be supplied through the gas purifying section 732A andthe particle filter 733A to the pressure regulator 738C. The pressureregulator 738C may decrease the pressure fluctuation of the boosted gas.

Thereby, the pressure controller 736A may be supplied with the boostedgas of which pressure fluctuation has been decreased as with the firstembodiment.

When the pressure inside the tank 711A reaches the target pressure Pt,the jet 27A is outputted from the nozzle 718A, such that the droplet 27is generated.

3.5 Fourth Embodiment 3.5.1 Configuration

FIG. 7 schematically illustrates a configuration of a target supplydevice according to a fourth embodiment.

A target supply device 7D of the fourth embodiment may have the sameconfiguration as that of the target supply device 7A of the firstembodiment except the provision of a gas supply section 73D.

A gas supply section 73D may have the same configuration as that of thegas supply section 73A of the first embodiment except that a purifier739D is provided instead of the gas purifying section 732A and theparticle filter 733A.

The purifier 739D may be disposed at a segment between a connectingportion between the pipe 721A and the pipe 723A and a connecting portionbetween the pipe 721A and the booster 731A. The purifier 739D may be apurifier manufactured by SAES Pure Gas, Inc. (model no.: SP70-203,pressure resistance: 206.8 atmospheres (about 21.0 MPa), filtrationrating of particle filter: 0.003 μm), for example.

3.5.2 Operation

Operations performed by the target supply device 7D are described.

Hereinbelow, the description of the operations which are the same asthose of the first embodiment will be omitted.

When the pressure controller 736A controls the pressure such that thepressure inside the tank 711A reaches the target pressure Pt in thetarget supply device 7D, the booster 731A may boost the gas suppliedfrom the gas line 730A. The boosted gas, which has been boosted by thebooster 731A, can be supplied to the purifier 739D. The purifier 739Dmay remove the impurities and particles in the boosted gas. The boostedgas, from which the impurities and particles have been removed, can besupplied through the buffer tank 734A and the pressure controller 736Ato the tank 711A.

When the pressure inside the tank 711A reaches the target pressure Pt,the jet 27A is outputted from the nozzle 718A, such that the droplet 27is generated.

3.6 Fifth Embodiment 3.6.1 Configuration

FIG. 8 schematically illustrates a configuration of an EUV lightgeneration system according to a fifth embodiment.

An EUV light generation system 11E of the fifth embodiment may include aplurality of EUV light generation apparatuses 1E and gas supply sections73A. The number of the gas supply sections 73A is less than that of theEUV light generation apparatuses 1E. Each of the EUV light generationapparatuses 1E may be used together with the laser apparatus 3 and theexposure apparatus 6. The EUV light generation apparatus 1E may have thesame configuration as that of the EUV light generation apparatus 1A ofthe first embodiment except the provision of a target supply device 7E.The target supply device 7E may have the same configuration as that ofthe target supply device 7A of the first embodiment except that each ofthe target supply devices 7E is not provided with the gas supply section73A.

A lid section 714A of the target generator 71A may be provided with apipe 901E. The pipe 901E may penetrate through the lid section 714A,such that a first end thereof is located inside the tank 711A. A valveV3 may be disposed in the middle of the pipe 901E.

The number of the gas supply sections 73A may be only one, for example.

A pipe 902E may be provided to a first end of the pipe 721A in a statethat the pipe 902E is split into the number of the EUV light generationapparatuses 1E. A valve V4 may be respectively connected in the middleof the pipe 902E after being split. A second end of the pipe 902E may beconnected to a second end of the pipe 901E through a joint 911E.

Thereby, the boosted gas within the pipe 721A can be supplied to theinside of the tank 711A of each of the plurality of EUV light generationapparatuses 1E. Further, after the valve V3 and the valve V4 are closed,the joint 911E is operated so as to cancel the connection between thepipe 901E and the pipe 902E, and thereby each of the target supplydevices 7E can be independently removed to be subjected to maintenance.

3.6.2 Operation

Operations performed by the EUV light generation system 11E aredescribed.

Hereinbelow, the description of the operations which are the same asthose of the first embodiment will be omitted.

A worker opens the valve V3 and the valve V4 connected to the EUV lightgeneration apparatus 1E for generating the EUV light among a pluralityof the EUV light generation apparatuses 1E constituting the EUV lightgeneration system 11E, so that the boosted gas can be supplied to thetank 711A. Thereafter, in the EUV light generation system 11E, when thepressure controller 736A controls the pressure so that the pressureinside the tank 711A reaches the target pressure Pt, the booster 731Amay boost the gas supplied from the gas line 730A. The boosted gas,which has been boosted by the booster 731A, can be supplied to thepressure controller 736A through the gas purifying section 732A, theparticle filter 733A, and the buffer tank 734A. The boosted gas of whichpressure has been adjusted by the pressure controller 736A can besupplied to the tank 711A of the EUV light generation apparatus 1E whosevalve V3 and valve V4 are opened.

When the pressure inside the tank 711A reaches the target pressure Pt,the jet 27A is outputted from the nozzle 718A, such that the droplet 27is generated.

Thereby, in the case where the extent of decrease in the pressure insidethe tank 711A is smaller than a predetermined value when the targetsupply device 7E outputs the droplet 27 and the flow rate of the boostedgas to be supplied by the gas supply section 73A may be small, it can besufficient to use only one gas supply section 73A to supply a pluralityof the tanks 711A with the boosted gas enough to output the droplets 27.Since the number of the gas supply sections 73A is smaller than that ofthe tanks 711A, the cost can be lower. Additionally, when the targetsupply device 7E is independently removed to be subjected tomaintenance, it can be unnecessary to stop operations performed by othertarget supply devices 7E.

3.7 Sixth Embodiment 3.7.1 Configuration

FIG. 9 schematically illustrates a configuration of an EUV lightgeneration system according to a sixth embodiment.

A EUV light generation system 11F of the sixth embodiment may include aplurality of EUV light generation apparatuses 1F and gas supply sections73F. The number of the gas supply sections 73F is less than that of theEUV light generation apparatuses 1F. Each of the EUV light generationapparatuses 1F may be used together with the laser apparatus 3 and theexposure apparatus 6. The EUV light generation apparatus 1F may have thesame configuration as that of the EUV light generation apparatus 1A ofthe first embodiment except the provision of a target supply device 7F.The target supply device 7F may have the same configuration as that ofthe target supply device 7A of the first embodiment except that each ofthe target supply devices 7F is not provided with the gas supply section73F.

The lid section 714A of the target generator 71A may be provided with apipe 901E such that a first end of the pipe 901E is located inside thetank 711A. A valve V3 may be disposed in the middle of the pipe 901E.

The number of the gas supply sections 73F may be only one, for example.The gas supply section 73F may include the booster 731A, the gaspurifying section 732A, the particle filter 733A, the buffer tank 734A,the pressure sensor 735A, and the pressure controller 736A.

The number of each of the boosters 731A, the gas purifying sections732A, the particle filters 733A, and the buffer tanks 734A may be one.The number of each of the pressure sensors 735A and the pressurecontrollers 736A may be the same as that of the EUV light generationapparatuses 1F.

The booster 731A may be connected to a second end of the pipe 721A. Thebooster 731A may be connected to the gas line 730A through the pipe722A. The pipe 721A may be provided with the gas purifying section 732A,the particle filter 733A, and the buffer tank 734A, as with the firstembodiment.

A pipe 902E may be connected to the first end of the pipe 721A in astate that the pipe 902E is split into the number of the EUV lightgeneration apparatuses 1F. A valve V4 may be respectively connected inthe middle of the pipe 902E after being split. The second end of thepipe 902E may be connected to the second end of the pipe 901E through ajoint 911E.

A first end of a pipe 903F may be connected to a segment between thevalve V3 and the lid section 714A in the pipe 901E. The pressure sensor735A may be provided to a second end of the pipe 903F.

The first valve V1 of the pressure controller 736A may be provided to asegment between the valve V4 and the pipe 902E after being split at aside on which the pipe 721A is located. A first end of the pipe 904F maybe connected to a segment between the first valve V1 and the valve V4 inthe pipe 902E. The second valve V2 of the pressure controller 736A maybe provided in the middle of the pipe 904F. A second end of the pipe904F may be opened.

The first valve V1 and the second valve V2 may be electrically connectedto the valve controller 737A of the pressure controller 736A. Thepressure sensor 735A may be electrically connected to the valvecontroller 737A with use of an electric wire 911F and an electric wire912F which are electrically connected to each other through a connector913F.

Thereby, the boosted gas within the pipe 721A can be supplied to theinside of the tank 711A of each of the plurality of EUV light generationapparatuses 1F. Further, after the valve V3 and the valve V4 are closed,the joint 911E is operated so as to cancel the connection between thepipe 902E and the pipe 901E, at the same time as the connector 913F isoperated so as to cancel the connection between the electric wire 911Fand the electric wire 912F, and thereby each of the target supplydevices 7F can be independently removed to be subjected to maintenance.

3.7.2 Operation

Operations performed by the EUV light generation system 11F aredescribed.

Hereinbelow, the description of the operations which are the same asthose of the first embodiment and the fifth embodiment will be omitted.

A worker may open the valve V3 and the valve V4 connected to the EUVlight generation apparatus 1F for generating the EUV light among aplurality of the EUV light generation apparatuses 1F constituting theEUV light generation system 11F, so that the boosted gas can be suppliedto the tank 711A. Thereafter, the target control apparatus 80A of theEUV light generation apparatus 1F for generating the EUV light maytransmit a signal to the valve controller 737A and set the pressureinside the tank 711A to the target pressure Pt. The target pressure Ptof each of the tanks 711A may be the same or different. In the casewhere the target pressure Pt of each of the tanks 711A is different, aplurality of the target generators 71A each having the nozzle hole 719Awith a different diameter may be used so as to output the droplet 27 atthe same speed, or a plurality of the target generators 71A each havingthe nozzle hole 719A with the same diameter may be used so as to outputthe droplet 27 at a different speed.

In the EUV light generation system 11F, the booster 731A may boost thegas supplied from the gas line 730A such that the pressure inside thetank 711A reaches the target pressure Pt. The boosted gas, of whichpressure has been adjusted by the pressure controller 736A, can besupplied to the tank 711A of the EUV light generation apparatus 1F ofwhich valve V3 and valve V4 are opened.

When the pressure inside the tank 711A reaches the target pressure Pt,the jet 27A is outputted from the nozzle 718A, such that the droplet 27is generated.

Thereby, even in the case where the target pressure Pt of each of thetanks 711A is different, the boosted gas at an appropriate pressure canbe supplied to each of the tanks 711A.

3.8 Seventh Embodiment 3.8.1 Configuration

FIG. 10 schematically illustrates a configuration of a target supplydevice according to a seventh embodiment.

A target supply device 7G of the seventh embodiment may have the sameconfiguration as that of the target supply device 7A of the firstembodiment except the provision of a gas supply section 73G.

The gas supply section 73G may have the same configuration as that ofthe gas supply section 73A of the first embodiment except that the gassupply section 73G is provided with a pressure sensor 735G1, a pressuresensor 735G2, a first line valve V1G, a second line valve V2G, a thirdline valve V3G, a fourth line valve V4G, and a sequence controller 90G,in addition to the pressure regulator 738C of the third embodiment.

According to this embodiment, the pressure regulator 738C may functionas not only the pressure stabilizer but also the pressure loweringsection. The pressure of the gas supplied from a gas facility of asemiconductor factory to the gas line 730A may be as low as 0.5 MPa, andthe booster 731A may boost the pressure of the gas up to 50 MPa. Then,the pressure regulator 738C as the pressure lowering section lowers thepressure of the gas, which has been boosted by the booster 731A, down to40 MPa, so as to decrease the pressure fluctuation which occurs due tothe operation of the booster 731A. Impurities can be generated frommoving elements of the pressure regulator 738C in some cases.Accordingly, in the case where the pressure regulator 738C is disposedat an upstream side from the gas purifying section 732A, the impuritiesgenerated in the pressure regulator 738C can be collected by the gaspurifying section 732A.

A pipe 724G1 may be connected to a segment between the booster 731A andthe pressure regulator 738C in the pipe 721A. A first end of the pipe724G1 may be connected to the side surface of the pipe 721A. A secondend of the pipe 724G1 may be provided with the pressure sensor 735G1.

A pipe 724G2 may be connected to a segment between the particle filter733A and the pipe 723A in the pipe 721A. A first end of the pipe 724G2may be connected to the side surface of the pipe 721A. A second end ofthe pipe 724G2 may be provided with the pressure sensor 735G2.

The pressure sensors 735G1 and 735G2 may be electrically connected to asequence controller 90G. The pressure sensors 735G1 and 735G2 mayrespectively measure the pressures inside the pipe 724G1 and the pipe724G2 and transmit signals corresponding to the measured pressures tothe sequence controller 90G.

A first line valve V1G may be disposed at a segment between the pressureregulator 738C and the gas purifying section 732A in the pipe 721A. Asecond line valve V2G may be disposed in the middle of the pipe 723A. Athird line valve V3G may be disposed in the pipe 721A such that thethird line valve V3G is closer to the tank 711A than the connectingportion of the pipe 724A is. A pipe 725G may be connected to the pipe721A such that the pipe 725G is closer to the tank 711A than third linevalve V3G is. A first end of the pipe 725G may be connected to the sidesurface of the pipe 721A. A second end of the pipe 725G may be opened. Afourth line valve V4G may be disposed in the middle of the pipe 725G.

Each of first to fourth line valves V1G, V2G, V3G, and V4G may be anelectromagnetically driven valve, or may be any one of a gate valve, aball valve, a butterfly valve, and the like. Each of the first to fourthline valves V1G, V2G, V3G, and V4G may be a valve of the same type or adifferent type. The sequence controller 90G may be electricallyconnected to the first to fourth line valves V1G, V2G, V3G, and V4G.

The sequence controller 90G may determine whether or not an absolutevalue of the difference in pressure between the pressure P1 measured bythe pressure sensor 735G1 and a first target pressure P10 is equal to orless than a first acceptable value ΔP1 and whether or not an absolutevalue of the difference in pressure between the pressure P2 measured bythe pressure sensor 735G2 and a second target pressure P20 is equal toor less than a second acceptable value ΔP2. Then, the sequencecontroller 90G may control the opening/closing of the first to fourthline valves V1G, V2G, V3G, and V4G based on the result of thedetermination. Thereby, the gas from the gas line 730A can be suppliedto the inside of the tank 711A so that the pressure inside the tank 711Ais stable at the target pressure P20. When the pressure inside the tank711A reaches the target pressure P20, the jet 27A is outputted from thenozzle 718A, and the droplet 27 (see FIG. 1 and FIG. 2) can be generatedin accordance with the vibration of the nozzle 718A.

When the first valve V1 and the first and second line valves V1G and V2Gare opened, the boosted gas from the gas line 730A can be supplied tothe buffer tank 734A and the third line valve V3G above the pipe 721Athrough the pressure controller 736A. Thereafter, when the third linevalve V3G is opened, the boosted gas can be supplied to the inside ofthe tank 711A of the target generator 71A. In the case where the secondvalve V2 and the fourth line valve V4G are closed, it is possible toprevent the boosted gas inside the pipe 721A, buffer tank 734A, and tank711A from being discharged from the second end of the pipe 725A to theoutside of the pipe 725A and from the second end of the pipe 725G to theoutside of the pipe 725G. Consequently, when the second valve V2 and thefourth line valve V4G are closed at the same time as the first valve V1and the first, second, and third line valves V1G, V2G, and V3G areopened, the pressure inside the tank 711A can be boosted up to thepressure corresponding to the pressure after being lowered by thepressure regulator 738C. Thereafter, the pressure inside the tank 711Acan be maintained at the pressure corresponding to the pressure afterbeing lowered by the pressure regulator 738C.

When the first line valve V1G is closed, it is possible to prevent theboosted gas from being supplied through the pipe 721A to the inside ofthe tank 711A. When the second valve V2, and the third and fourth linevalves V3G and V4G are opened, due to the difference in pressure betweenthe pipe 721A and the outside of the tank 711A, the boosted gas insidethe pipe 721A and the tank 711A can be discharged from the second end ofthe pipe 725A to the outside of the pipe 725A and from the second end ofthe pipe 725G to the outside of the pipe 725G. Further, when the firstvalve V1 and the second line valve V2G are closed, and the second valveV2 and the third and fourth line valves V3G and V4G are opened, thepressure inside the tank 711A may be lowered while the gas at apredetermined pressure remains in the buffer tank 734A.

3.8.2 Operation

Operations performed by the target supply device 7G are described byreferring to the flowchart shown in FIG. 11. Hereinbelow, thedescription of the operations which are the same as those of the firstembodiment will be omitted. Further, the description is based on theassumption that the fourth line valve V4G remains to be in a closedstate.

Firstly, in a waiting state before the target generator 71A is attached,the sequence controller 90G may close the first to third line valvesV1G, V2G, and V3G (ST1). Next, the sequence controller 90G may activatethe booster 731A, such that the pressure in the upstream side from thefirst line valve V1G becomes closer to a predetermined first targetpressure P10 (ST2). Here, the first target pressure P10 may be thepressure to be boosted by the booster 731A, for example, 50 MPa.

The sequence controller 90G may determine whether or not the absolutevalue of the difference in pressure between the pressure P1 detected bythe pressure sensor 735G1 and the first target pressure P10 is equal toor less than a first acceptable value AP1 (ST3). The first acceptablevalue AP1 may be, for example, in the range of 0 to 1 MPa. In the casewhere it is determined that the absolute value of the difference inpressure is equal to or less than the first acceptable value ΔP1, thesequence controller 90G may maintain the waiting state.

Thereafter, the target generator 71A may be attached to the chamber 2(ST4). An attachment sensor (not shown in the drawings) may detectwhether or not the target generator 71A is attached to the chamber 2.The attachment sensor may be, for example, a mechanical limit switch, amagnetic sensor, an optical sensor, or the like.

In the case where it is confirmed that the target generator 71A has beenattached (ST5), in a line filling process, a gas filling switch (notshown in the drawings) may be pushed (ST6), such that the gas line 730Ais supplied with gas at the pressure of approximately 0.5 MPa. In thecase where the gas is always supplied from the gas facility to the gasline 730A, the process ST6 may be omitted. Thereafter, the sequencecontroller 90G may open the first line valve V1G, so as to boost the gasin the line in the downstream side from the first line valve V1G. Atthis time, the pressure regulator 738C may lower the pressure down to alevel necessary for the tank 711A. The necessary pressure may be in therange of 10 to 90 MPa, for example, 40 MPa.

Next, the sequence controller 90G may open the second line valve V2G, soas to connect the buffer tank 734A to the line (ST7). The buffer tank734A can decrease the pressure fluctuation, which has not been removedcompletely by the pressure regulator 738C, so as to make it possible toperform pressure control with a high degree of accuracy by the pressurecontroller 736A. Then, the sequence controller 90G may determine whetheror not the absolute value of the difference in pressure between thepressure P2 detected by the pressure sensor 735G2 and the second targetpressure P20 is equal to or less than the second acceptable value ΔP2(ST8). Here, the second target pressure P20 may be pressure inside thepipe located between the particle filter 733A and the pressurecontroller 736A, for example, 40 MPa. The second acceptable value ΔP2may be, for example, in the range of 0 to 1 MPa. In the case where thesequence controller 90G determines that the absolute value of thedifference in pressure is equal to or less than the second acceptablevalue ΔP2, the procedure may proceed to a discharging process.

In the discharging process, the set value of the pressure in thepressure controller 736A may be set to a pressure P3 (ST9). The pressureP3 may be, for example, approximately 0.1 MPa, that is pressure at whichthe droplet 27 is not discharged. The sequence controller 90G may openthe third line valve V3G in a state that the first line valve V1G andthe second line valve V2G are opened (ST10). Then, the temperaturecontroller 784A may control the heater power source 782A, such that theheater 781 is heated up to a predetermined temperature which is equal toor greater than a melting point of tin (232° C.) as the target material270, for example, 280° C., so as to melt the tin (ST11). Thereafter, thepressure controller 736A may change the set value of the pressure to apressure P4 (ST12). The pressure P4 is a discharge pressure, and may be40 MPa, for example. As a result, the droplet 27 can be discharged (seeFIG. 1 and FIG. 2) (ST13).

Incidentally, in the case where the droplets 27 are discharged at higherspeed so as to further increase the interval of the droplets 27, thefirst target pressure P10 may be set to approximately 100 MPa, thesecond target pressure P20 may be set to approximately 90 MPa, and thepressure P4 may be set to approximately 90 MPa, for example. Incontrast, in the case where the droplets 27 may be discharged at a lowerspeed, the first target pressure P10 may be set to approximately 10 MPa,the second target pressure P20 may be set to approximately 8 MPa, andthe pressure P4 may be set to approximately 8 MPa, for example.

3.9 Eighth Embodiment 3.9.1 Configuration

FIG. 12 schematically illustrates a configuration of a target supplydevice according to an eighth embodiment.

A target supply device 7H of the eighth embodiment may have the sameconfiguration as that of the target supply device 7G of the seventhembodiment except the provision of a gas supply section 73H.

The gas supply section 73H may have the same configuration as that ofthe gas supply section 73G of the seventh embodiment except that abuffer tank 734H as a pressure accumulator is provided.

A pipe 723H may be connected to a segment between a connecting portionbetween the pipe 721A and the booster 731A and a connecting portionbetween the pipe 721A and the pipe 724G1. A first end of the pipe 723Hmay be connected to the side surface of the pipe 721A. The buffer tank734H may be provided to a second end of the pipe 723H. Pressure which ishigher than the pressure of the gas to be supplied to the tank 711A maybe accumulated in the buffer tank 734H. The pressure may be in the rangeof 15 to 100 MPa, for example.

3.9.2 Operation

Operations performed by the target supply device 7H are described byreferring to the flowchart shown in FIG. 13. Hereinbelow, thedescription of the operations which are the same as those of the seventhembodiment will be omitted.

During the waiting state in the operation of the target supply device7H, a process ST14 in which high-pressure gas, which has been boosted bythe booster 731A, is filled into the buffer tank 734H may be addedbetween the process ST2 and the process ST3.

In the process ST14, the buffer tank 734H may be filled with gas atpressure higher than the pressure of the gas to be supplied to the tank711A. In the case where the first target pressure P10 of the gas boostedby the booster 731A is 50 MPa, for example, the buffer tank 734H may befilled with the gas at the pressure of 50 MPa. Since the buffer tank734H, which has been preliminarily filled with the gas at the pressure(50 MPa) higher than the pressure (40 MPa) of the gas to be supplied tothe tank 711A, is prepared, the high-pressure gas can be supplied at aflow rate greater than a generative capacity of the booster 731A in ashort period of time, at the time of filling the line in the downstreamside from the pressure regulator 738C with the high-pressure gas. Thegenerative capacity of the booster 731A may mean an amount of the gaswhich can be boosted by the booster 731A per unit time.

3.10 Variation

Incidentally, each of the target supply device and the EUV lightgeneration system may have a configuration as follows.

In the first to sixth embodiments, the booster 731A may be configured todetect the pressure of the third space 777A by the pressure sensor andmove the air piston 772A and the gas piston 773A vertically by drivingthe motor. Hereinbelow, the booster for moving the air piston 772A andthe gas piston 773A vertically by the drive air is referred to as a“booster of preferred embodiments”, and the booster for moving the airpiston 772A and the gas piston 773A vertically by driving the motor isreferred to as a “booster of modified examples” in some cases.

In the second embodiment, three or more boosters may be provided. In thefirst and third to sixth embodiments, two or more boosters may beprovided. In the case where two or more boosters are provided, only theboosters of preferred embodiments may be provided, only the boosters ofmodified examples may be provided, or both of the boosters of preferredembodiments and the boosters of modified examples may be provided.

In the case where the extent of pressure fluctuation of the boosted gassupplied from the booster 731A is less than 10% of the pressure afterbeing adjusted by the pressure controller 736A in the first to sixthembodiments, the buffer tank 734A and the pressure regulator 738C maynot be provided. In the first, second, and fourth to sixth embodiments,the pressure regulator 738C may be provided instead of the buffer tank734A.

In the first to third, fifth, and sixth embodiments, at least one of thegas purifying section 732A and the particle filter 733A may not beprovided, and a position at which the gas purifying section 732A is tobe disposed may be replaced with a position at which the particle filter733A is to be disposed. In the first to third, fifth, and sixthembodiments, the purifier 739D may be provided instead of the gaspurifying section 732A and the particle filter 733A.

In the fourth embodiment, the purifier 739D may not be provided.

According to the seventh and eighth embodiments, the sequence controller90G directly reads out the value detected by the pressure sensor 735G1,so as to detect the pressure of the boosted gas, however, the presentinvention is not limited thereto. For example, in the case where thebooster 731A includes a boost controller and a pressure sensor, theboost controller may read out the value detected by the pressure sensorand activate the booster 731A. When the conditions of the process ST3(see FIG. 11 and FIG. 13) are satisfied, a signal may be outputted tothe sequence controller 90G so as to notify the completion of thewaiting state.

The above-described embodiments and the modifications thereof are merelyexamples for implementing the present disclosure, and the presentdisclosure is not limited thereto. Making various modificationsaccording to the specifications or the like is within the scope of thepresent disclosure, and other various embodiments are possible withinthe scope of the present disclosure. For example, the modificationsillustrated for particular ones of the embodiments can be applied toother embodiments as well (including the other embodiments describedherein).

The terms used in this specification and the appended claims should beinterpreted as “non-limiting.” For example, the terms “include” and “beincluded” should be interpreted as “including the stated elements butnot limited to the stated elements.” The term “have” should beinterpreted as “having the stated elements but not limited to the statedelements.” Further, the modifier “one (a/an)” should be interpreted as“at least one” or “one or more.

What is claimed is:
 1. A target supply device configured to supply atarget material comprising: a tank configured to store the targetmaterial; a nozzle connected to the tank and configured to output thetarget material; and a gas supply section configured to supply the tankwith gas, the gas supply section comprising: a pipe having a first endconnected to the tank; and a booster connected between a gas line and asecond end of the pipe and configured to boost gas supplied from the gasline and supply the pipe with the boosted gas.
 2. The target supplydevice according to claim 1, wherein the gas supply section furthercomprises a pressure controller configured to adjust pressure of theboosted gas in the pipe.
 3. The target supply device according to claim1, wherein the gas supply section further comprises a pressure loweringsection configured to lower pressure of the gas, which has been boostedby the booster, down to a predetermined pressure.
 4. The target supplydevice according to claim 3, wherein the gas supply section furthercomprises a pressure accumulator disposed between the booster and thepressure lowering section.
 5. The target supply device according toclaim 1, wherein the gas supply section further comprises a gaspurifying section configured to remove impurities from the gas which hasbeen boosted by the booster.
 6. The target supply device according toclaim 5, wherein the gas supply section further comprises a pressurelowering section configured to lower pressure of the gas, which has beenboosted by the booster, down to a predetermined pressure.
 7. The targetsupply device according to claim 1, wherein the gas supply sectionfurther comprises a particle filter configured to remove particles fromthe gas which has been boosted by the booster.
 8. The target supplydevice according to claim 7, wherein the gas supply section furthercomprises a pressure lowering section configured to lower pressure ofthe gas, which has been boosted by the booster, down to a predeterminedpressure.
 9. The target supply device according to claim 1, wherein thegas supply section further comprises a pressure stabilizer configured tostabilize the pressure of the gas which has been boosted by the booster.10. The target supply device according to claim 9, wherein the gassupply section further comprises a pressure lowering section configuredto lower pressure of the gas, which has been boosted by the booster,down to a predetermined pressure.
 11. An EUV light generation apparatuscomprising a target supply device configured to supply a targetmaterial, the EUV light generation apparatus irradiating the targetmaterial with a laser beam to generate EUV light, the target supplydevice comprising: a tank configured to store the target material; anozzle connected to the tank and configured to output the targetmaterial; and a gas supply section configured to supply the tank withgas, the gas supply section comprising: a pipe having a first endconnected to the tank; and a booster connected between a gas line and asecond end of the pipe and configured to boost gas supplied from the gasline and supply the pipe with the boosted gas.
 12. The EUV lightgeneration apparatus according to claim 11, wherein the gas supplysection further comprises a pressure controller configured to adjustpressure of the boosted gas in the pipe.
 13. The EUV light generationapparatus according to claim 11, wherein the gas supply section furthercomprises a pressure lowering section configured to lower pressure ofthe gas, which has been boosted by the booster, down to a predeterminedpressure.
 14. The EUV light generation apparatus according to claim 13,wherein the gas supply section further comprises a pressure accumulatordisposed between the booster and the pressure lowering section.
 15. TheEUV light generation apparatus according to claim 11, wherein the gassupply section further comprises a gas purifying section configured toremove impurities from the gas which has been boosted by the booster.16. The EUV light generation apparatus according to claim 15, whereinthe gas supply section further comprises a pressure lowering sectionconfigured to lower pressure of the gas, which has been boosted by thebooster, down to a predetermined pressure.
 17. The EUV light generationapparatus according to claim 11, wherein the gas supply section furthercomprises a particle filter configured to remove particles from the gaswhich has been boosted by the booster.
 18. The EUV light generationapparatus according to claim 17, wherein the gas supply section furthercomprises a pressure lowering section configured to lower pressure ofthe gas, which has been boosted by the booster, down to a predeterminedpressure.
 19. The EUV light generation apparatus according to claim 11,wherein the gas supply section further comprises a pressure stabilizerconfigured to stabilize the pressure of the gas which has been boostedby the booster.
 20. The EUV light generation apparatus according toclaim 19, wherein the gas supply section further comprises a pressurelowering section configured to lower pressure of the gas, which has beenboosted by the booster, down to a predetermined pressure.